PRODUCTION AND COLLECTION OF SEED OYSTERS 
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Table 15.— Observations of the height of the tide and the time of slack water, Onset Bay near Shell Point, 
August 3, 1928 
Time 
Height 
of tide 
Current 
Time 
Height 
of tide 
Current 
Time 
Height 
of tide 
Current 
Time 
Height 
of tide 
Current 
a. m. 
8.03 
8.15 
8.30 
4 4.7 
4 5.4 
4 7. 2 
Flood. 
Do. 
Do. 
a. m. 
8.43 
8.49 
8.50 
4 7.3 
4 7.6 
4 7.6 
Slack water. 
Do. 
Ebb. 
a. m. 
8.54 
9.30 
9.45 
4 7. 5 
4 4. 2 
4 4 
Ebb. 
Do. 
Do. 
a. m. 
9.55 
10.15 
4 3.7 
4 0.2 
Ebb. 
Do. 
It can be noticed from the examination of Table 15 that the maximum height of 
tide occurred 6 minutes after the slack water and that the period when there were no 
surface currents lasted only 7 minutes. On account of slow currents which can not 
HOUR A.M. P.M. 
Figure 18. — Surface flood currents in the channel at Shell Point, September 7 and 8, 1927 
be recorded with the current meter, such observations are possible only on very 
calm days. It is unfortunate that weather conditions did not permit repeating 
them several times and determining the time of slack water at low tide; the latter, 
however, is of less significance, because the zone of the heaviest setting in Onset 
Harbor is above low-water mark. 
The velocity of tidal current in any inshore body of water is determined by two 
factors: The volume of water that flows through the channel past a given point, 
and the cross sectional area at this point. In a shallow bay like Onset Bay with an 
irregular shore line and numerous bars obstructing the free passage of water, the 
tidal movements do not conform with the comparatively simple motion that takes 
place in an unobstructed channel or in a wide, deep river. On account of changes 
